Update to work with latest graphics/shadergraph

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Inspector/Views/IMGUISlotEditorView.cs

             else
                 return;
 
-            Add(new IMGUIContainer(onGUIHandler) { executionContext = presenter.GetInstanceID() });
+            Add(new IMGUIContainer(onGUIHandler));
         }
 
         void Vector4OnGUIHandler()

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Views/MaterialNodeView.cs

             {
                 m_ControlsContainer.Add(new IMGUIContainer(controlData.OnGUIHandler)
                 {
-                    name = "element",
-                    executionContext = controlData.GetInstanceID(),
+                    name = "element"
                 });
                 m_CurrentControls.Add(controlData);
             }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Importers/ShaderSubGraphImporter.cs

 
         var graphAsset = ScriptableObject.CreateInstance<MaterialSubGraphAsset>();
         graphAsset.subGraph = graph;
-        ctx.SetMainAsset("MainAsset", graphAsset);
+        ctx.AddObjectToAsset("MainAsset", graphAsset);
+        ctx.SetMainObject(graphAsset);
     }
 }